miR-365 inhibits duck myoblast proliferation by targeting IGF-I via PI3K/Akt pathway

Area of Science:

• Molecular Biology
• Cell Biology
• Animal Science

Background:

• MicroRNA-365 (miR-365) is implicated in cancer cell proliferation and apoptosis.
• The role of miR-365 in myoblast proliferation, particularly in non-mammalian species, is not well understood.
• Understanding miR-365's function in myogenesis is crucial for muscle development research.

Purpose of the Study:

• To investigate the role of miR-365 in duck myoblast proliferation.
• To elucidate the molecular mechanism by which miR-365 affects myoblast proliferation.
• To identify potential targets of miR-365 involved in the PI3K/Akt signaling pathway.

Main Methods:

• Overexpression of miR-365 in duck myoblasts.
• Luciferase reporter assay to confirm direct targeting of insulin-like growth factor-I (IGF-I) 3'UTR.
• Quantitative real-time PCR to measure mRNA levels of PI3K, Akt, mTOR, and S6K.
• Inhibition of PI3K pathway using LY294002 to assess its role in miR-365's effect.

Main Results:

• Overexpression of miR-365 significantly inhibited duck myoblast proliferation.
• miR-365 was confirmed to directly target the 3'UTR of IGF-I, leading to its down-regulation.
• Enhanced miR-365 expression decreased mRNA levels of key signaling molecules: PI3K, Akt, mTOR, and S6K.
• Inhibition of the PI3K/Akt pathway using LY294002 abrogated the effects of miR-365 inhibitor on these signaling molecules.

Conclusions:

• miR-365 negatively regulates duck myoblast proliferation.
• The mechanism involves the direct targeting of IGF-I and subsequent modulation of the PI3K/Akt/mTOR/S6K signaling pathway.
• These findings reveal a novel role for miR-365 in regulating muscle cell growth via the IGF-I/PI3K/Akt axis.